Airlines are required by law to meet certain regulatory engine noise standards for their aircraft. Generally, known aircraft engine acoustic treatment systems consist of a segmented series of individual panels attached inside an engine fan case. The panels are typically located immediately aft of an engine/inlet attachment interface and forward of an engine fan assembly. At least one known engine acoustic treatment system includes multiple individual panels installed side by side around an interior surface of the engine fan case and/or other adjacent interior areas of an engine nacelle. In such known acoustic treatment systems panel acoustically active area is typically not available around the edge bands of each individual panel or at fastener locations. Acoustic area is also lost between each panel, between the panels and nacelle inlet structure, and between the panels and the nacelle engine structure adjacent the face of fan blades included in the fan assembly. Additionally, the number of panels included in the typical acoustic treatment system makes it difficult to ‘Tune’ the acoustic treatment to best match the source noise. That is, it is difficult to match the acoustic absorption characteristics of the acoustic treatment to the noise signature of a specific engine and associated fan assembly. Furthermore, typical noise treatment systems have numerous leak paths that allow air, and thus noise, to escape from the engine assembly. Further yet, in known acoustic treatment systems the high number of parts adds weight to the aircraft and increases labor and parts costs.
Therefore, it would be desirable to have an improved aircraft engine acoustic treatment system that will reduce aircraft engine noise to alleviate its adverse impacts on the passengers as well as the airport's neighboring communities. It would also be desirable to have an acoustic treatment system that increases acoustic area, improves engine performance, reduces aircraft weight and reduces labor and parts costs associated with installing the acoustic treatment system.